Carbon fibre and need for neck resets

[trion12]

I was wondering given the stiffness of carbon fibre about the need for neck resets over time. Given the newness of carbon fibre guitars we don't have any old ones to test this empirically.
Does anyone know if there has been any experimental evidence of changes in geometry of carbon fibre under stress over time?
TIA.

Aaron

[patticake]

i can't see how a neck reset would be possible on a carbon fiber guitar. the body and neck seem to be a single piece.

[murrmac123]

The question is a good one.

AFAIK, there isn't enough information available about manufacturing techniques from manufacturers like Rainsong, for example, even to hazard a guess about the likelihood, or feasibility, of neck resets.

[patticake]

well, i'm staring at my composite acoustics cargo, and the neck and body are a single piece. the only way to get the neck off would be with a hack saw

i know there's at least one carbon fiber guitar that uses a truss rod. perhaps that one has a removable neck.

[devellis]

I think the equivalent to a neck reset would have to be some re-shaping of the body, bending it backwards, in essence. I have no idea if such a thing is possible. As we know, neck resets aren't because the neck slips as much as because the body geometry changes in a way that results in the nut being raised, relative to the bridge (kind of "jelly-beaning" so to speak). I doubt that you could reverse this were it to happen on a carbon fiber guitar, but I certainly don't know that for a fact.

[JLS]

Originally Posted by patticake

i can't see how a neck reset would be possible on a carbon fiber guitar. the body and neck seem to be a single piece.

My Rainsong OM1000 has a bolted on neck. Rainsong says it's "bonded", as well, though that may refer to the fingerboard extension. I doubt anything will move, ever.

[tadol]

New materials, new technologies, new problems, new techniques -

Welcome to the cutting edge -

[deja]

What kind of environmental conditions could change the structure of a carbon fiber guitar over time? Isn't that their appeal, namely, there are no comparable conditions that could change the guitar's structure?

[gitnoob]

Originally Posted by deja

What kind of environmental conditions could change the structure of a carbon fiber guitar over time? Isn't that their appeal, namely, there are no comparable conditions that could change the guitar's structure?

160lbs of string tension relentlessly applied for many years?

I have no idea if carbon fiber deforms the way wood does. Supposedly it's more brittle and simply breaks.

[P_K]

carbon fiber does not bend with time, so it is no need to worry. the only reset you'd need on a carbon guitar is to adjust it to your specific need/likeness of feel/action. you do it adjusting saddle and nut. once it is the way you like it'll remain there for the rest of your life and your son's, grandson's... life

anyway, Rainsong does a line of model with truss-rod and Emerald guitars can incluide them is you ask for

[Steve Christens]

I can't imagine a carbon fiber guitar changing much with time under normal use.

BUT, remember that these instruments are not just carbon fiber construction - they are carbon fiber COMPOSITE construction. And that means the quality and characteristics of the epoxy resin are critical too. Under normal design conditions composite construction does not creep. But I once saw a carbon fiber composite boom on a sailboat irreversibly deform under load in the hot sun when the temp got too close to the Tg (softening temp) of the epoxy resin used. In that case they clearly used the wrong resin, and should have used once with a higher Tg.

I hope the various guitar manufacturers don't make the same mistake. But since they don't disclose what resin they use, it would probably be a good idea not to store your carbon fiber guitar outdoors in the hot sun!